The government of Khartoum delayed permission for an evacuation flight for three Ethiopian peacekeepers who were seriously wounded in a land mine explosion this week in Abyei.
The peacekeepers died while the UN desperately sought permission to fly them out of Abyei for medical care.One died on the spot when their vehicle hit a landmine.
Another seven peacekeepers injured in the blast remain hospitalized.
UN peacekeeping chief Alain Le Roy said Khartoum threatened to shoot down the helicopter if it flew without permission.
He added that it was difficult to say whether the lives of the three peacekeepers could have been saved if the helicopter had been allowed to take off immediately.
More than 1,500 Ethiopian troops have been deployed in Abyei out of a contingent of over 4,000 that forms UNISFA, the new UN Interim Security Force for Abyei.